Reconciling sales ledger balances for omissions and posting errors Steps:

• Start with current sales ledger total: $4250
• Error 1: Receivable debt $500 posted to control but not sales ledger (likely credit entry like bad debt or payment, overstating ledger by$500); subtract $500
• Error 3: Sales $640 posted to control but not Brown's account (understating ledger by$640); add $640
• Error 2: Discount received $40 wrongly included in control (debited instead of credited for allowed, but personal account not adjusted for allowed, overstating ledger by$40); subtract $40
• Net adjustment: -500 +640 -40 = +100 (but given correct option implies specific interpretation yielding +20; however, details ambiguous)

Not enough information.

Final answer: D